Hello everyone, I wrote this a few years ago as a general guide for myself and friends on DeviantArt. I finally finished revamping it as times have changes since I wrote the original article. The information below is based on years of research and first hand experience but everyone treats illnesses differently. This is just how I do it. There are a number of sources, including VIN (Veterinary Information Network) and BettaTalk.The Four Most Important Aspects of Betta Care Are:
1) Proper Water Changes
2) Warm Water (78*-82*F)
3) Varied Diet
4) Quarentine New Fish/Plants/Tankmates
If you do these 4 things, you can greatly reduce the chances of your betta getting sick.Things to keep on hand at all times
•Extra nets and 1 gallon containers
•Aquarium Salt (Aq.Salt)
•Epsom Salt (ES)
•Potassium Permanganate (PP)
•Quarantine tank (QT)Water Chemistry:
Before you treat your fish for everything under the sun, check the water chemistry. Toxic levels of Ammonia, Nitrites and Nitrates are extremely harmful and weaken your betta's immune system resulting in illness. Many petstores will test your water for free. Liquid tests are much more accurate than strip tests.
•If your fish look like they are lethargic, gasping for air or are swimming head down do a water change immediately because they probably have nitrate, nitrite, or ammonia poisoning. Do not use chemicals to remove them as they are ineffective. Prime does remove nitrites/nitrates but it is still most effective to do a water change.
•Extreme pH variation can also cause illness. Sand and porous rocks like sandstone or lava rock make water more basic (>7.0) while Indian almond leaves, peat moss and oak leaves make the water more acidic (<7.0).
•Are there chlorinates in the water? Did you forget to add the water conditioner? If so, quickly add your water conditioner!!
•Many issues can be cured by a simple water change so it should be the first thing you try.

Conservative Treatment Versus Medication:
There are two ways to treat a sick fish. One is the conservative route. It involves increased water changes and (usually) salt treatments. The other route is using medication. There are some illnesses that respond better to medication than water changes and salt, however most illnesses can be cured simply with a bit of TLC and salt. In general, you should always attempt conservative treatment methods before using medicines as medicines can be hard on your fish’s internal organs and over using medicine or not completing the treatment cycle can result in the creation of medicine-resistance bugs.

Therapeutic Additives:There are a number of things you can do for your betta to reduce stress and support their immune system. Indian Almond leaves, tannins, black water extracts, and peat moss pellets are all things that you can add to help prevent illness or help recovery. API Stress Coat and Kordon’s Fish Protector are water conditioners/additives that help slime coat production and skin repair. They can be added at any time your fish shows signs of illness.

True Fungal Infections
•Symptoms: White cottony like patches on its body or head, Lethargic, Not eating, Clamped Fins, Pale Colors
•Treatment: Conservative: Lower temperature below 76* F and treat with Aq.Salt at 1 tsp/gal. Increase water changes to 100% daily. Replace accurate amount of salt following water changes. Never continue salt treatments for more than 10 days. Medication: If Conservative treatment is ineffective after 10 days or you see the fungus spread rapidly during the course of conservative treatment, move to medication. Add “Fungus Eliminator” by Jungle, API Erythromycin, API Fungus Cure, API Triple Sulfa, OR Mardel’s Maracyn II. Change water every day and add a new dose of the same medication. Continue until all fungus has disappeared.

Tail rot or fin rot
•Symptoms: Betta’s fins and/or tail seem to be getting shorter and shorter or they seem to be falling apart and dissolving, Black or red along the edge of the betta’s fins/tail, Bloody tips, Behavior may not change
Treatment: Conservative: Treat with Aq.Salt at 1 tsp/gal. Increase water changes to 100% daily. Replace accurate amount of salt following water changes. Add Stress Coat to help repair tissue. If there is little to no improvement within the first 5 days, you can increase the salt dosage gradually to 2tsp/gal but do not continue any salt treatments past 10 days. Medication: If Conservative treatment is ineffective use API Tetracycline, API Fungus Cure, API Triple Sulfa, OR API Erythromycin. Also add Stress Coat to help regrowth. Continue until fins/tail stop receding and start showing some new growth.

Advanced Fin and Tail rot
•Symptoms: Fins and or tail start rotting away, usually starting from the edge, but sometimes it starts at the base of the fin (especially dorsal) and attacks the body directly. Diseases progresses rapidly as the tissues are being eaten away. Once fins have been consumed, rot will proceed onto the body. At this stage the disease is hard to reverse although the betta might continue to live for months if treated properly. If not treated, it will die promptly.
•Treatment: If the rot has advanced onto the body, skip conservative treatment. Do 100% daily water changes. Use a combination of Fungus Eliminator and Tetracycline. Continue until fins/tail stop receding and start showing some new growth. It may take up to 4 weeks to work, so don’t give up.

Fin Biting
•Symptoms: Not to be confused with Fin/Tail Rot, Fin or Tail biting is when a betta bites his own tail, tearing off pieces. Fins will be ragged, they will look like there are chunks missing, Fin loss can occur overnight, The tips of the fins are clean, no black or red edging, You may spot him swimming in circles, chasing his tail, There may be no other behavioral change
•Treatment:
Bettas bite their own tails out of boredom or misplaced aggression. To cure his boredom, try getting him a larger tank, move things around in the tank to spark his interest, put a mirror up to the tank a few times per day to let him exercise, offer a variety of foods, get him some tank mates (research into this first though), or put his tank next to another betta’s tank ect… Owners of fin biters often have to deal with their tendency for a lifetime but do what you can to draw his attention from his fins. When your betta does have a fin biting episode, it is important to keep his water extra clean to prevent infection. You can treat him for a few days with Aquarium Salt until you see regrowth but you do not want to overuse it. Using Stress Coat as the water conditioner will help fin regrowth.

Ick
•Symptoms: Betta has white dots (looks like he was sprinkled with salt) all over his body and head, even eyes. Lethargic, No appetite, Clamped Fins, Might dart and scratching against decor
•Treatment: You can treat Ick either conservatively or with medication. Ick is a parasite. Because ick is contagious, it is preferable to treat the whole tank when one fish is found to have it. Ick is temperature sensitive: Leave your betta in the community tank and raise temperature to 85 F. Then you can choose to treat with salt or medication. Conservative: Add 1 tsp/gal Aquarium Salt 3 times, 12 hours apart so that you end up with 3 times the normal concentration. Perform daily 100% water changes to remove fallen parasites before they can reproduce. Replace the water with the right amount of salt. Do not continue this treatment for more than 14 days. If it fails or you do not want to use salt, treat with Jungle’s Parasite Clear, API Super Ick Cure, or Kordon Rid Ich Plus. If your betta lives in a jar/bowl, then it can be difficult to heat the water. There are heaters for smaller containers, but you can also float the quarantine container in a larger heated tank during treatment. Do a full water change every day and add an appropriate amount of medication to the water.
•Alternative Treatment: Personally, I have not found Ick medications very effective. I prefer to use PP to treat all external parasites. In the past, I have used 3 or 4 different ick medications unsuccessfully, and every time I resort to PP which works like a charm. Do lots of research before using PP as it is a more dangerous chemical than most.

Velvet
•Symptoms: Can be found by shining a flashlight on your betta. If it looks like it is covered in fine gold of rust colored dust then it has velvet. Clamped Fins, no appetite, darting/rubbing, loss of color, lethargic
•Treatment: It is very contagious so you should treat the entire tank. Treat as you would treat Ick. PP is also my favorite for treating Velvet.

Popeye
•Symptoms: One or both eyes will swell and bulge out. It in itself can also be a symptom of Dropsy.
•Treatment: Usually not fatal if treated, but your betta might lose an eye. Conservative: If the swelling is extreme then use ES first. Perform 100% daily water changes. You may be able to treat the popeye with just Epsom and clean water. However, if the swelling goes down but the eyes remain cloudy/white, then switch to Aq.Salt at 1tsp/gal or use medications. Do not combine Aq.Salt with medications but you can continue to use ES during medical treatments. Medication: If ES or Aq.Salt do not do the trick or it is a serious case of popeye, then combine the ES with API Tetracycline, API Fungus Cure, API General Cure, API Triple Sulfa, OR Mardel’s Maracyn.

Dropsy
•Symptoms: Your betta will have a bloated belly and raised scales. They will look like a pine cone. This is usually a fatal disease caused by an internal bacterial infection resulting in internal organ failure but many have had success bringing fish back when treated quickly.
Early Symptoms: Swollen eyes (important), Gray belly (important), Clamped fins, Lethargy. If your fish has swollen eyes and a gray belly, I suggest that you treat it for Dropsy.
•Treatment: If you spot the early signs of Dropsy then treat him/her with ES at 1-2tsp/gal and Jungle’s Anti-Parasite pellets while performing 100% daily water changes. It helps to increase the temperature to 84*F. If he/she has begun Pineconning then do the full course as described below:
Performing daily 100% water changes. Increase the temperature to 84*F. Add 1-2 tsp/gal Epsom Salt. Use API General Cure OR API Erythromycin OR Maracyn II and/or Maracyn for best results. Feed something containing Metronidazole, for example, Jungle’s Anti-Parasite pellets. If caught early, Dropsy is curable.

Swim Bladder Disease (SBD)/Bloat
•Symptoms: Betta has trouble swimming, maybe he can’t stay upright and can only swim on his side.
•Treatment: This is not a contagious or fatal illness. If it isn’t congenital (aka a condition that he/she has had since birth), then it is caused by over feeding or feeding the wrong foods. Bettas will typically recover after a day or two of Epsom Salt treatments (1-2tsp/gal) and fasting. You can help prevent a reoccurrence by switching to a better pellet food, feeding less and offering a more varied diet. To make it easier for the betta to eat and breath, you can make the water shallower. You can offer him/her frozen daphnia (sold at Petsmart) as daphnia will help him/her pass stool. DO NOT FEED THEM PEAS.

External Parasites
•Symptoms: You may see parasites (other than ick) or you may not. Pay special attention to the area around the gills and fins. May dart and rub against decor, lose interest in food, lethargy, color loss
•Treatment: Some parasites can be treated conservatively with Aquarium Salt. For salt treatments, treat as you would with Ick. If conservative treatment does not work or if you have extenuating circumstances then there are a number of medications you could use. API’s General Cure and Jungle’s Parasite Clear fizz tablets are both affective ways to kill parasites. Do not combine with Aq.Salt.
•Alternative Medicines: I like PP for all stubborn external infections. It has never failed me, but it should only be used as a last resort.

Internal Parasites
•Symptoms: Betta is losing weight but eating normally and acting lethargic.
He/she might dart or rub against decor.
•Treatment: These can be hard to fight and can get confused with the fatal disease Tuberculosis. Perform daily 100% water changes (if possible, for larger aquariums change 3/4). Make sure you carefully clean the gravel to remove eggs/larva. Aq.Salt does not seem to be affective against internal parasites. I find combining ES with an anti-parasite med is best. Treat with 1-2tsp/gal Epsom Salt combined with either Jungle’s Anti-Parasite Pellets, Jungle’s Parasite Clear Fizz tabs or API General Cure. PP is also effective against internal parasites.

Bacterial Infection/Open Red Sores
•Symptoms: Betta has open red sores or red patches (that aren’t ammonia burns), lethargy, no apetite, clamped, sits at bottom or top, color loss.
•Treatment: Perform daily 100% water changes and clean the gravel thoroughly (at least 3/4 water change for larger tanks). Treat the entire tank. Treat conservatively with Aq.Salt at 1-2tsp/gal but do not continue for more than 10 days. If that fails, use API Tetracycline, API Erythromycin, API Triple Sulfa OR Mardel’s Maracyn I & II. PP is also effective.

Tuberculosis
•Symptoms: Fish will start acting sick for no apparent reason. They could just die. Symptoms include weight loss, lethargy, open sores, deformities (scoliosis, bent spine), raised scales, fin and tail rot, gray lesions, and many others. Generally, if your fish are dying in large amounts everyday, it is probably TB. BEWARE HUMANS CAN CONTRACT TUBERCULOSIS FROM FISH, IT IS A POTENTIALLY DEADLY DISEASE.
•Treatment: There is no known cure, it will generally kill all fish that come in contact with it. It is highly contagious. Bleach does not kill it so throw away all supplies...

Inflamed Gills
•Symptoms: One or both gills will not close all the way and may appear red. The fish will be gasping for air and subsequently die.
•Treatment: Isolate sick fish. Depending on the cause, there are different treatments. If it is genetic then there is no cure. If it was caused by nitrate/nitrite/ammonia poisoning (BAD HUSBANDRY) then treat with 1tsp/gal Aq.Salt and Stress Coat while performing daily 100% water changes. If it is a bacterial infection, then you can treat conservitably with 1-2tsp/gal Aq.Salt for up to 10 days. If that does not work then use API Tetracycline, API Erythromiacin, API Triple Sulfa, OR Maracyn.

Septicemia(Red Streaks)
•Symptoms: Bloody red streaks across the body and/or fins, lethargic, loss of apetite, clamped, gasping for air, bloated, ulcers.
•Treatment: Septicemia is caused by an internal bacterial infection. From what I’ve read, it can be due to compromised digestion as a result of rapid drops in temperature. Since Nitrite poisoning can also cause red streaks, check for that first. I do not know if it can be treated conservatively as I have never tried. Though it is not contagious, isolate sick fish. Perform daily 100% water changes. Treat with API Tetracycline, API Erythromiacin, Mardel’s Maracyn II OR Jungle’s Fungus Clear/Eliminator. If you are treating with something that does not contain Metronidoxole then combine the treatment with Jungle’s Anti-Parasite pellets. During treatment, use 1tsp/gal Aq.Salt and Stress Coat (as directed on bottle) to help prevent secondary infections.

Body Slime Infection
•Symptoms: Your betta is covered in a white film. It may just be in a few areas and may rise of the skin a bit. Lethargy, clamped, loss of apetite, may have cloudy eyes.
•Treatment: Body Slime infections or Slime Coat Sloughing are due to bacterial infections. Perform daily 100% water changes. Use 1tsp/gal Aq.Salt for up to 10 days. If that does not work then use API Tetracycline, API Fungus Cure, API Triple Sulfa, OR Jungle’s Lifeguard.

Columnaris
•Symptoms: White spots on mouth, edges of scales and fins, Cottony Growth that eats away at the mouth, Fins rapidly disingrate, starting at the edges
Gray areas around head and gills, As the disease progresses the gray lesions may change in color to yellow/brown/red, Lesions often occur in front of the dorsal causing a “saddleback” appearance, Lethargic, Loss of appetite, Clamped, Gasping for air
•Treatment: There are 2 versions of Columnaris: chronic and acute. Chronic Columnaris can take days to progress while acute can kill within a day. It is contagious so isolate sick fish. If more than one fish shows symptoms then treat the entire tank. Perform daily 100% water change in small tanks or ¾ water change in larger tanks. Make sure to clean the gravel. Treat with Aq.Salt: add 1 tsp/gal Aquarium Salt 3 times, 12 hours apart so that you end up with 3 times the normal concentration. Do NOT raise the temperature as it thrives in temps over 85*F, however, lowering the temperature does not seem to help fight it. Combine salt treatment with Mardel’s Coppersafe, Maracyn I & II, API Erythromycin, OR API Triple Sulfa, combined with Jungle’s Fungus Eliminator (if possible).

Hole in the Head Disease
•Symptoms: lesions (holes) will appear around the head area, Lethargy, Loss of appetite
•Treatment: HITH can be treated conservatively with Aquarium salt. Add 1 tsp/gal Aquarium Salt 3 times, 12 hours apart so that you end up with 3 times the normal concentration and remember not to continue this for more than 10 days. Keep the temperature between 80-82*F and perform daily 100% water changes. If conservative treatment fails then use API General Cure OR Jungle’s Parasite Clear fizz tablets.

Stress
•Symptoms: It’s hard to say for sure. But maybe your betta is lethargic, not eating, hiding, staying in a corner or at the bottom of the tank, he might look a bit pale or dart away when you get close to the tank. It could be a mild infection of some sort though too so be careful.
Treatment/Prevention: If your betta is housed with other fish then isolate him and see if he get better. His tank mates might be harassing him. On the other hand, some bettas become depressed when isolated. Other causes could be too much or too little light, too much current, too much activity near the tank, the temperature might be too low. Try changing things up, move the aquarium to a more isolated area and see if he gets better. Or if he’s on a food strike, offer live foods. If he is lonely, place the tank where he can see other fish. Make sure there are places to hide when he is stressed.

Well, college has stolen every free second I've had so I've really been neglecting you guys! Sorry :( Here are a few more diseases and treatments. I still check my inbox everyday so feel free to PM me with questions/problems and I will respond asap! Hope these help!

Costia

Symtomes: 8-15micrometer long flagellates may be visible. Affected fish may do swinging movements, scratch against decor, stop eating, have labored breathing, have bluish-grayish slime coating, clamped fins, red tints on body, may have fin disintegration, gills may be covered in mucous and anemic.

Treatment: Remove all fish from tank. Treat fish with Aquarium Salt baths: Use 2.5 tablespoon/gal for 10-15 minutes then place fish in clean water for 10 minutes then move it into the hospital tank. If fish becomes obviously stressed then remove it from the salt bath quickly. Do this daily for 3 days. Use 2tsp/gal in the hospital tank to prevent secondary infection and perform daily 100% water changes. Sterilizing the tank: Costia cannot survive at temps above 86*F so increase the temp of the main tank to 88*-90*F for 48 hours. The parasites will die due to both the temperature and lack of host and it will be safe to reintroduce your fish as long as they have finished treatment. Another option is treatment with once daily Potassium Permanganate Baths (RESEARCH THIS THOROUGHLY AND PM ME) for 5 days with 2tsp/gal Aquarium Salt in the hospital tank to prevent secondary infections. Quarantining new fish and plants will help prevent infestations.

Red-Sore Disease
Also known as: Aeromonas hydrophila, Motile Aeromonas Septicemia, Ulcer Disease and it is really the later stages of Hemmorhagic Septicemia. This disease is "different" from Hemmorhagic Septicemia in that the fish will have ulcers. The pictures are pretty gruesome so you can look it up if you are so inclined...

Symptoms: Fish are lethargic, lay on the bottom, refuse food, may bloat, scales may raise (dropsy) or shed, and fish will develop red blotches that eventually turn into ulcers with white edges and a red center.

Treatment: Since it can be the later stages of Hemmorhagic Septicemia, it is often fatal unless you begin treating immediately after you see the ulcer. Though the ulcer is external, it is an internal gram-negative bacterial infection so medication is necessary. Feed an anti-bacterial medication such as Kanamycin, Furazolidone or Nitrofurazone. Specialty stores often sell the as pre-medicated flakes and they are available on Aquabid. Use 2tsp/gal Aquarium Salt in the water to prevent secondary infection and perform daily 100% water changes. It is usually caused by poor water conditions so keep your tanks clean.